Any state other than the ground state of an atom or molecule.
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The most expensive metal in the world
Do you think the most expensive metal is gold? No! On earth there are more valuable metals. But we need to divide the value of metals that occur in nature, and metals - isotopes, which are obtained in special laboratories. Let’s look at natural metals first.
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Why do copper products change color, and what is the name of the process?
Probably, every person wants to know, why over time the copper turns green and becomes bloomed. This is easy to explain: that film is called patina.
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Chemistry of the sky
Chemistry can teach us about the composition of celestial bodies and determine their age.
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Gas of rotten eggs
If you happen to break a rotten egg, then you know the smell of hydrogen sulfide, because the stench of the spoiled egg depends on of its presence in rotting protein substances.
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Use of diamonds
Diamond is a crystalline modification of pure carbon formed in the deep interior of the Earth, in the upper mantle at depths of more than 80-100 kilometers, at exceptionally high pressure and temperature. It is the most precious stone, the hardest and most wear-resistant mineral, the most...
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Cis-Trans Isomerism
A type of geometrical isomerism related to the angles between like ligands.
Forbidden Zone
A relatively large energy separation between an insulator's highest filled electron energy band and the next higher energy vacant band. Beginning in the fourth energy level, a set of seven degenerate orbitals per energy level, higher in energy than s, p, and d orbitals of the same energy level.
Open Sextet
Refers to species that have only six electrons in the highest energy level of the central element (many Lewis acids).
Crystalline Solid
A solid characterized by a regular, ordered arrangement of particles.
Fluorescence
Absorption of high energy radiation by a substance and subsequent emission of visible light.
Supersaturated Solution
A solution that contains a higher than saturation concentration of solute, slight disturbance or seeding causes crystallization of excess solute.
Spectrum
Display of component wavelengths (colours) of electromagnetic radiation.
Le Chatelier's Principle
States that a system at equilibrium, or striving to attain equilibrium, responds in such a way as to counteract any stress placed upon it.
If a stress (change of conditions) is applied to a system at equilibrium, the system shifts in the direction that reduces stress.
Lewis Dot Formula (Electron Dot Formula)
Representation of the core of a molecule, ion or formula unit by showing atomic symbols and only outer shell electrons.
Net Ionic Equation
Equation that results from canceling spectator ions and eliminating brackets from a total ionic equation.
